Asst. Prof @CarnegieMellon, @amazon Scholar, Prev: Visiting Researcher @Meta, Postdoc @Stanford, Ph.D. @RiceUniversity, Large-Scale ML, a fan of Dota2.

Joined November 2011
As data centers hit power limits, AI model needs an energy-efficient scaling axis. โšก Embedding scaling grows model capacity with minimal additional serving energy. STAPLE brings this to pretrained LLMsโ€”without restarting pretraining from scratch.
๐Ÿง  How can we keep scaling LLMs with minimal changes in their serving energy? DeepSeekโ€™s Engram and our concurrent work STEM showed the promise of static sparse memory: large embedding tables with efficient access. But can mature pretrained models learn to use a newly added memory within a limited training budget, avoiding costly pretraining from scratch? ๐Ÿš€ Introducing STAPLE: a recipe to extend pretrained models' abilities with static sparse memory. Serving energy per token stays close to dense and >50% below MoE upcycling in high-throughput regime. Scalable capacity, interpretable memory, and compatibility with MoE upcycling - without any meaningful increase in serving cost. ๐Ÿงต Paper: arxiv.org/abs/2610.12599 Code: github.com/Infini-AI-Lab/STAโ€ฆ Website: infini-ai-lab.github.io/STAPโ€ฆ
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Beidi Chen retweeted
Today, weโ€™re excited to launch the Datology Curation Studio, customizable frontier data curation for every team training its own models. Data quality is the ultimate compute multiplier, and Curation Studio makes it easy for everyone.
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Beidi Chen retweeted
Splash 1.3.0 is out! At launch we focused on decode speed. This time we worked on the wait before the first token. Watch the part where we come back to a project. With SSD offloading on, the first token takes about a second instead of 19.
Splash 1.3.0 is out, and it's about the wait before your local agent starts answering โšก If you switch projects and come back, SSD offloading brings the first token down from 19 seconds to 1. New tasks start 1.5ร— faster, thanks to the Neural Engine. All on a 24 GB M6 Mac.
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Weโ€™re open-sourcing lithos-metal ๐Ÿš€ Megakernels + DSpark speculative decoding run Qwen3.8-27B at 200+ tokens/s/user peak on one @Apple M5 Max. Ultra-fast inference on your laptop. Try it with any coding agent in one command. Code: github.com/lithos-ai/lithos-โ€ฆ Tech blog: lithosai.com/blog/lithos-metโ€ฆ
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The next frontier would be agents that get smarter as you use them. ๐Ÿš€ Our new ServeLearnBench puts continual self-improvement to the testโ€”and reveals whatโ€™s holding it back.
How well can agents continually self-improve from serving experience? Weโ€™re excited to introduce our new benchmark, ๐’๐ž๐ซ๐ฏ๐ž๐‹๐ž๐š๐ซ๐ง๐๐ž๐ง๐œ๐ก: Real-world deployment is not a one-time test of capability. The knowledge agents need is often hidden and can change over time. ServeLearnBench tests whether agents can infer, apply, and revise this knowledge from interaction. Across 5 learning harnesses ร— 6 models, we find: 1. ๐‹๐š๐ซ๐ ๐ž ๐ฅ๐ž๐š๐ซ๐ง๐ข๐ง๐  ๐ ๐š๐ฉ๐ฌ ๐ซ๐ž๐ฆ๐š๐ข๐ง. Agents can solve tasks when the hidden policy is given, but struggle to discover it from experience. 2. ๐๐จ ๐Ÿ๐ซ๐ž๐ž ๐ฅ๐ฎ๐ง๐œ๐ก ๐Ÿ๐จ๐ซ ๐š๐๐š๐ฉ๐ญ๐š๐ญ๐ข๐จ๐ง. Continual learning can be costlyโ€”and can even degrade already-correct behavior. 3. ๐„๐ฑ๐ฉ๐ฅ๐จ๐ซ๐š๐ญ๐ข๐จ๐ง ๐ข๐ฌ ๐š ๐ค๐ž๐ฒ ๐›๐จ๐ญ๐ญ๐ฅ๐ž๐ง๐ž๐œ๐ค. Better exploration strongly correlates with better adaptation.
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Beidi Chen retweeted
Kernel agents can already beat hand-tuned kernels. Spinning up more agents is easy, but scaling GPU evaluation is still hard and expensive. What happens when the agents scale faster than the GPUs? Meet KCoral ๐Ÿชธ: a lightweight shared GPU benchmark environment for agentic kernel development. ๐Ÿง‘โ€๐Ÿ’ป Agents keep writing and revising code in their own workspace. โšก Evaluation is sent to KCoral, which schedules a shared GPU pool and returns correctness and timing. ๐ŸŒ Scale across multiple GPUs and nodes through a unified API endpoint. ๐Ÿ”’ Per-request isolation with only milliseconds of execution overhead. By overlapping CPU compilation with GPU work across requests, KCoral further speeds up kernel evaluation. On a single NVIDIA B200, this translates to 2.58ร— the throughput of sequential local execution.
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๐Ÿค”engram is finally in
๐Ÿš€ Introducing DeepSeek-V4.1-Flash: smarter, faster, more efficient. ๐Ÿ”น Introducing the smallest model in our new architecture family, with native visual understanding. ๐Ÿ”น Designed for greater capability, faster inference, higher throughput, and scaling to larger models. 1/6
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DFlash 2 is here! Qwen3.8-27B at 70 tok/s on an M5 Max MacBook Pro. โšก Up to 4.6ร— the speed of autoregressive decoding, with the same output. This is the next generation of DFlash, seeded at Z Lab and upgraded at Inco AI. Get one more accepted token on every pass, for free! inco.ai/blog/dflash2/
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๐Ÿ“ขAI is taking over the infrastructure it runs onโ€”and already doing better. FlashRT achieves up to 70ร— lower latency and 3.6ร— higher throughput across five real-time apps, even delivering stronger results on less human-optimized AMD GPUs than on NVIDIA. We used to handcraft static systems, but human expertise doesnโ€™t scale. In the agent era, every application should have an end-to-end system customized by AI for its workload and hardware. FlashRT is an early step toward that future.
AI is now building the infrastructure it runs on. Getting real-time multimodal applications โ€” including live avatars, voice agents, video world models โ€” to actually run in real time takes serious manual systems work. Turns out a coding agent can do all the engineering work for you: up to 70ร— lower latency and 3.6ร— higher throughput, across 5 real-time apps. Today we release FlashRT โšก, an agent harness for real-time systems implementations and optimization. The developer writes only a simple reference spec, and the agent handles the rest end-to-end, producing efficient deployments across a range of GPU budgets in one shot, with no human intervention. โœ… Validated on 5 real-time applications that combine interactive video generation, text-to-speech, LLMs, etc. โœ… Runs on both NVIDIA and AMD GPUs; the agent optimizes for the hardware youโ€™re on โœ… Can easily compose with third-party serving engines, the agent automatically implements orchestration ๐Ÿ“„ Paper: arxiv.org/abs/2607.18171 ๐ŸŒ Website: infini-ai-lab.github.io/flasโ€ฆ ๐Ÿ”— GitHub: github.com/Infini-AI-Lab/Flaโ€ฆ ๐Ÿงต1/5
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Beidi Chen retweeted
Today we're also opening the weights for Muse Glimmer, a great 30B parameter dense model that can run locally. Soon we'll also release the weights for Muse Spark 1.2, our latest foundation model. Meta is a strong supporter of open source and I'm proud of these releases. Congrats to @alexandr_wang and the MSL team for all your great work on these models.
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First keynote talk of the day for AdaptFM @ #ICML2026 from @BeidiChen on "When AI Starts Building AI". adaptfm.gitlab.io/talks/whenโ€ฆ
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lol Iโ€™ve been assuming Claude > GPT on basically everything. Turns out reasoning โ‰  strategy.
๐€๐ซ๐ž ๐ ๐จ๐จ๐ ๐ซ๐ž๐š๐ฌ๐จ๐ง๐ž๐ซ๐ฌ ๐š๐ฅ๐ฐ๐š๐ฒ๐ฌ ๐ ๐จ๐จ๐ ๐ฌ๐ญ๐ซ๐š๐ญ๐ž๐ ๐ข๐ฌ๐ญ๐ฌ? Our new project, AI Battle Arena, suggests the answer is no: Claude models are strong at many reasoning-heavy tasks, like coding. But in hidden-information poker, Claude models stayed honest and paid an honesty tax. GPT-5.5 did much better because it was ๐ฐ๐ข๐ฅ๐ฅ๐ข๐ง๐  ๐ญ๐จ ๐๐ž๐œ๐ž๐ข๐ฏ๐ž ๐ข๐ญ๐ฌ ๐จ๐ฉ๐ฉ๐จ๐ง๐ž๐ง๐ญ๐ฌ. AI Battle Arena ๐ŸŽฒ is an open-source arena for evaluating frontier LLMs in strategic interaction, from poker to Gomoku to Colonel Blotto. ๐๐ฅ๐จ๐ : aibattlearena.com/blog.html ๐‹๐ž๐š๐๐ž๐ซ๐›๐จ๐š๐ซ๐: aibattlearena.com/leaderboarโ€ฆ
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Rollout generation is becoming a central bottleneck in long-context RL says everyone โ€” and recent efforts from Cursor @cursor_ai and Fireworks @FireworksAI_HQ show how just important disaggregating rollout and training is today. Excited to share Sparrow๐Ÿค, which makes sparse rollout practical and accelerate stable long-context RL. Check it out!
RL is painfully slow ๐Ÿ˜ญ โ€” bottlenecked by super-long CoT rollout. ๐Ÿ”ญ Sparse attention should help, but naive sparse rollout hits a brutal efficiencyโ€“stability tradeoff: A tedious trial-and-error sparsity sweep for each dense policy is required before an actual RL run. ๐ŸคSparrow chirps no more pain! Introduce Sparrow: Sparse Rollout for stable and efficient long-context RL. Sparrow finds that: ๐Ÿ’กAs long as we keep the tail distribution mismatch throughout the sparse rollout above a critical threshold, the RL training will be stable. ๐Ÿ’กEven cooler! Through comprehensive control studies of Qwen3-1.7B, 4B, 8B thinking models RL with 40K rollout max length, the critical threshold stays constant across model sizes. ๐Ÿ’กSparrow then finds the optimal dynamic sparse schedule to reach the threshold with minimal cost. ๐Ÿ’กSparrow's findings are empirically validated to generalize in Qwen3-14B, and hold on both Math and Coding RL. ๐ŸคSparrow empirically helps achieve 2.2ร— / 2.4ร— / 2.0ร— rollout speedup on Qwen3 1.7B / 4B / 8B thinking models, while keeping training stability over extended RL steps. We release the ๐Ÿคbird in the following formats. [1/n] Paper: arxiv.org/abs/2606.08446 Code: github.com/Infini-AI-Lab/Spaโ€ฆ Blog: infini-ai-lab.github.io/sparโ€ฆ
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๐Ÿค Inference-time sparse attention for RL is finally working. Turns out the real challenge wasnโ€™t sparsityโ€”it was getting asymmetric off-policy rollouts to stay stable. Sparrow discovers a robust stability threshold that lets us push sparsity to the limit: ~2ร— faster rollouts, minimal tuning, and stable long-CoT RL.
RL is painfully slow ๐Ÿ˜ญ โ€” bottlenecked by super-long CoT rollout. ๐Ÿ”ญ Sparse attention should help, but naive sparse rollout hits a brutal efficiencyโ€“stability tradeoff: A tedious trial-and-error sparsity sweep for each dense policy is required before an actual RL run. ๐ŸคSparrow chirps no more pain! Introduce Sparrow: Sparse Rollout for stable and efficient long-context RL. Sparrow finds that: ๐Ÿ’กAs long as we keep the tail distribution mismatch throughout the sparse rollout above a critical threshold, the RL training will be stable. ๐Ÿ’กEven cooler! Through comprehensive control studies of Qwen3-1.7B, 4B, 8B thinking models RL with 40K rollout max length, the critical threshold stays constant across model sizes. ๐Ÿ’กSparrow then finds the optimal dynamic sparse schedule to reach the threshold with minimal cost. ๐Ÿ’กSparrow's findings are empirically validated to generalize in Qwen3-14B, and hold on both Math and Coding RL. ๐ŸคSparrow empirically helps achieve 2.2ร— / 2.4ร— / 2.0ร— rollout speedup on Qwen3 1.7B / 4B / 8B thinking models, while keeping training stability over extended RL steps. We release the ๐Ÿคbird in the following formats. [1/n] Paper: arxiv.org/abs/2606.08446 Code: github.com/Infini-AI-Lab/Spaโ€ฆ Blog: infini-ai-lab.github.io/sparโ€ฆ
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mythos will be bad ON PURPOSE on ai "frontier llm research" tasks, this is very very sad for the research community also the fact that this is un purpose not visible to the user is crazy
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Vortex builds a layer for the current AI agents to make themselves more efficient, if you view AI agents as a species. We are soon to see AI agents directly program on an FPGA, defining efficient and expressive architecture, writing efficient low-level implementations, and training themselves. And, I do not know what can stop this. At that moment, whether AI can conduct research on something novel (rather than simply replicate what humans can already do) will determine whether 2025-2026 is a real genesis moment.
๐ŸŒ€ Introducing Vortex โ€” sparse attention designed by AI agents, efficient at scale. ๐Ÿ“ˆ Same accuracy, way more throughput โ€” across every model we tried ๐Ÿ‘‡ ๐Ÿ”น GLM-4.7-Flash (MLA) โ†’ 4.7ร— faster ๐Ÿ”น MiniMax-M2.7 (229B) โ†’ 1.37ร— faster ๐Ÿ”น Qwen3-1.7B (agent-discovered!) โ†’ 3.46ร— faster ๐Ÿค– How? An agent writes a flow in a few lines of Python; Vortex compiles it into fused kernels in a real serving stack (SGLang) and benchmarks it end-to-end. ๐Ÿ—๏ธ The design: a Python frontend (vFlow) over a page-centric tensor abstraction (vTensor) + a serving-integrated backend. ๐Ÿ“„ arxiv.org/abs/2606.06453 ๐Ÿ’ป github.com/Infini-AI-Lab/vorโ€ฆ ๐ŸŒ infini-ai-lab.github.io/vortโ€ฆ ๐Ÿ“š infini-ai-lab.github.io/vortโ€ฆ
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Come and check out AstraFlow's new release~ While recursive agents are becoming one of the most exciting directions in agentic AI, we include this RL recipe in AstraFlow v0.1.1 showing how powerful dynamic sub-agent workflows can be in real-world coding tasks.
๐Ÿš€ AstraFlow v0.1.1 is out! New in this release: โ€ข Dynamic recursive agents RL recipe โ€ข Megatron training backend Inspired by dynamic agent workflows like @claudeai, this release reproduces the recursive agent RL recipe, where models learn to automatically spawn sub-agents to solve subtasks. (The implementation is based on the awesome Recursive Agent Optimization paper by @apurvasgandhi, @gneubig, @aviral_kumar2: arxiv.org/abs/2605.06639) With existing RaaS support via @sgl_project and training backends including FSDP and Megatron, AstraFlow is moving toward a more flexible stack for large-scale agentic RL. โญ Repo: github.com/Infini-AI-Lab/astโ€ฆ ๐Ÿ“– Dynamic agents recipe: infini-ai-lab.github.io/astrโ€ฆ
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๐Ÿ“ขVortex feels like an early glimpse of recursive self-improvement for ML systems: agents discovering better architectures, compiling them into real serving stacks, and shifting the bottleneck from "can it code?" to "can we still steer it?" AI building AI just went from theory to benchmark chart.
๐ŸŒ€ Introducing Vortex โ€” sparse attention designed by AI agents, efficient at scale. ๐Ÿ“ˆ Same accuracy, way more throughput โ€” across every model we tried ๐Ÿ‘‡ ๐Ÿ”น GLM-4.7-Flash (MLA) โ†’ 4.7ร— faster ๐Ÿ”น MiniMax-M2.7 (229B) โ†’ 1.37ร— faster ๐Ÿ”น Qwen3-1.7B (agent-discovered!) โ†’ 3.46ร— faster ๐Ÿค– How? An agent writes a flow in a few lines of Python; Vortex compiles it into fused kernels in a real serving stack (SGLang) and benchmarks it end-to-end. ๐Ÿ—๏ธ The design: a Python frontend (vFlow) over a page-centric tensor abstraction (vTensor) + a serving-integrated backend. ๐Ÿ“„ arxiv.org/abs/2606.06453 ๐Ÿ’ป github.com/Infini-AI-Lab/vorโ€ฆ ๐ŸŒ infini-ai-lab.github.io/vortโ€ฆ ๐Ÿ“š infini-ai-lab.github.io/vortโ€ฆ
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Happy to see more RL systems moving toward this deployment shape. This has been one of the core ideas behind AstraFlow since our early design: large-scale agentic RL should move beyond trainer-centered โ€œengine modeโ€ and toward independently managed rollout/inference and training systems, connected by a clean rollout + weight-sync contract. In AstraFlow (github.com/Infini-AI-Lab/astโ€ฆ), we have been building toward this direction through rollout/trainer service decoupling, bring-your-own rollout service, flexible dataflow, and support for heterogeneous rollout backends. Excited to see the broader community converging on this architecture. I believe this is where large-scale agentic RL infrastructure is heading.
Most RL frameworks are moving from โ€œengine modeโ€ to โ€œserver modeโ€. slime goes one step further: the RL job does not need to own the rollout servers at all. Bring your own SGLang fleet, already deployed and managed by your serving system. slime connects to it, registers it with the router, generates rollouts, and syncs updated actor weights via NCCL or disk-based full/delta transport. This is the deployment shape we believe large-scale agentic RL is moving toward: training and inference as independently managed systems, connected by a clean rollout + weight-sync contract.
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